You can't redeem Infinity Vista codes if you're already an Infinity(PCVR + VR Glasses) subscriber. Changing your subscriber identity from Infinity to Infinity Vista will result in the immediate impact of being unable to use all PCVR Infinity content.
Remember, if you're a Infinity subscriber, you're already entitled to use all Vista content.
See the difference between Infinity and Infinity Vista: What is the difference between Infinity and Infinity Vista?